Tapered slot antennas, also known as Vivaldi antennas, have been developed for use in various applications. Usually, the width of the slot increases exponentially with distance from the feed point. In a typical implementation, the antenna is provided as orthogonal arrays of elements formed by conductive surfaces that define tapered slots therebetween. The conductive surfaces are usually formed on conventional printed circuit boards. More particularly, arrays of elements can be formed by using numerous printed circuit boards assembled into intersecting rows and columns in the form of a lattice type array. Accordingly, such antenna arrays are sometimes referred to as “Vivaldi egg crate arrays”. These antennas typically provide a bandwidth of about 3:1 or 4:1, although some designs provide a bandwidth of about 10:1.
Although such designs can be effective, they can also be complex and difficult to manufacture. For example, in a typical Vivaldi array, multiple rows of elements can be provided by arranging multiple parallel rows of substrates having plated elements formed thereon. In order to provide a dual-polarized antenna, additional elements can be formed on multiple parallel columns of substrates having plated elements formed thereon that are arranged perpendicular to the rows of substrates. The rows and/or columns are slotted where they intersect, to form a plurality of cruciform conductive structures. However, such assemblies are prone to defects. For example, proper operation of the arrays requires a good electrical connection between orthogonal plated elements of the individual cruciform conductive structures, which is difficult to achieve. Moreover, the multiple boards are difficult to align and assemble.
The difficulty of manufacturing a typical Vivaldi array is compounded by the large number of array elements that must be combined to produce the antenna aperture. In addition, the electronics behind the aperture that drive individual array elements have been difficult to connect to the array elements. The complexity of such antenna systems is further compounded where dual-polarization operation is a required feature of the antenna. Conventional egg crate designs also make it difficult to incorporate chips, such as integrated circuits, on the circuit boards comprising the array.